I wouldn't say they last forever. My aeron is about 15 years old, and it's starting to get some wobble in the main stem. (There might be a bearing that i can re

I wouldn't say they last forever. My aeron is about 15 years old, and it's starting to get some wobble in the main stem. (There might be a bearing that i can replace, but I haven't looked into it.) Also I never did understand the +/- dial on the side. It increases the stiffness of the chair, but I have to crank it about 5-8 times every few days. It feels like the mechanics are wearing out. (And my back is bugging me more recently, but that may just be me getting old.)